Transcript Document

Organs of the
Respiratory System
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Nose
Pharynx
Larynx
Trachea
Bronchi
Lungs
Accessory Structures
• Thorax
• Diaphragm
The Nose
The nose (naso or rhino) acts as entrance
for air and exit for carbon dioxide. A
ciliated epithilial mucus membrane lines
the nose and much of the respiratory
tract. It serves as a filter for dust and
other foreign material. It warms and
moistens entering air and has olfactory
receptors
The nostrils (nares) are paired
openings. The nostrils vary in
pliability and expandability. The
horse has pliable and expandable
nostrils because mouth breathing
is not characteristic. The
expandability accommodates the
increased need for oxygen
The Pharynx
This is a musculomembranous
saclike structure. The upper
portion is attached to the base of
the skull and the lower portion
unites with the esophagus. The
pharynx unites with the nasal
chambers, mouth, larynx and
eustasian tubes.
The pharynx is divided into three
parts:
*nasopharynx
*oropharynx
*laryngopharynx
The pharynx is used as passage
for both air and food. Depending
on the species it may also have a
roll in vocalization
The Larynx
This is commonly called the voice
box and is located just below the
pharynx and it serves as a passage
for air. The epiglottis is a lid like
structure that prevents food from
entering the airway during
swallowing
The larynx plays an important
role is creating sound. Air passes
through the glottis during
expiration causing a vibration,
producing a sound.
(video)
The Trachea
also called the windpipe is a
tube formed of smooth muscle
with numerous C shaped rings
of cartilage embedded in the
tissue. These rings prevent
collapse of the structure.
The Bronchi
the ends of the trachea separates into
smaller airways called the primary
bronchi
The bronchi is lined with a
ciliated mucous membrane and
have C shaped cartilage rings.
These rings become complete as
the bronchi enter the lungs. They
then divide into smaller branches
called the secondary branches
and these divide into bronchioles
which further divide into aveolar
ducts
The aveolar ducts terminate into
the aveolar sacs which are
minute, squamous epithelium
lined spaces that allow the lungs
to achieve the primary function
of oxygen and carbon dioxide
exchange.
As the bronchioles get smaller,
the cartilage rings begin to
disappear. There are no rings in
the aveolar ducts, sacs or aveoli.
The lungs are the primary
structures of the respiratory
system. The lungs occupy
almost the entire thoracic space.
Each lung contains millions of
aveoli and capillaries.
The lungs are encased in a serous
membrane called the visceral
pleura. The thoracic cavity is
lined with another membrane
called the parietal pleura. These
membranes reduce the friction
during repiration
The space between these
membranes is called the pleural
cavity or potential space.
The thorax (chest cavity) is lined
with a membrane similar to the
covering of the lungs. This
allows the lubrication of both
surfaces during respiration This
membrane is divided into the:
*right pleural cavity
*left pleural cavity
*mediastinum
The mediastinum contains the
heart, thymus, esophagus,
trachea, bronchi, nerves, arteries,
veins and lymphatic vessels.
The Diaphragm:
This is a dome shaped
musculomembranous partition
separating the thoracic and
abdominal cavity. It attaches to
the lumbar and abdominal
cavities. It attaches to the lumbar
vertebra, lower ribs and sternum
The diaphragm is the primary
muscle of respiration. During
inspiration, it contracts, flattens
and lowers. This increases the
capacity of the thoracic cavity.
On expiration the diaphragm
relaxes and returns to it’s normal
position
Video part 2 and 3
WARNING!!!!
This video of the anatomy of
humans….it is graphic.
The process of respiration:
The respiratory cycle is divided
into three parts:
*inspiration
*expiration
*rest : the interval between
inspiration and expiration
Respiration involves oxygen
being passed throughout the body
by circulation and carbon dioxide
wastes being exhaled. The
amount of oxygen retained by
tissue depends on the need.
Tissue does not store oxygen and
tissue only takes in as much
oxygen as it needs.
During exercise the oxygen
requirement can be more than
doubled. The flow of air in and
out of the lungs depends on
changes in the thoracic cavity.
Inspiration and expiration are in
accordance with the pressure
differences between the
atmosphere and air in the lungs
Tidal volume (TV):
the volume of air inspired or
expired during ordinary
respiration
Inspiratory reserve volume
(IRV):
the maximum volume of air that
can be forcibly inspired in
addition to tidal air.
Expiratory reserve volume
(ERV):
the volume of air that can be
forcibly expelled in addition to
tidal air. Some air will always
be trapped in the alveoli no
matter how forcibly an animal
exhales due to intrathoracic
pressure.
Residual Volume (RV):
The volume of air trapped in the
alveoli
Minimal volume:
the small amount of air left in the
alveoli after a total lung collapse.
When the thoracic pressure is
equal to the atmospheric pressure
Vital capacity (VC):
the largest amount of air that can
be moved in and out of the lungs.
The sum of the total of
inspiratory and expiratory
reserve volumes plus the tidal
volume
The nerves from the brain that
pass down the chest wall and
diaphragm to control respiration
Vagus nerve:
originates in the brain and sends
branches to the larynx, heart,
bronchi, esophagus, stomach, liver
and abdomen.
Phrenic nerve:
originates in the cervical spine
and passes to the diaphragm
Thoracic nerve:
originates in the thoracic spinal
cord, these are the nerves of the
muscles of the thorax